What’s Causing that Brown Spot in My Lawn?

June 21, 2013

I want to help you become your own brown lawn detective. To see how to approach this subject this year I looked back at some of my older blog postings about lawn insect, fungus and other problems that can cause your lawn to turn brown during summer weather. I decided the best way I could help you diagnose your own lawn problems is to make it easy for you to find the info and pictures you need. I have two links to help. The first is a link to a posting I did last summer that will help narrow down the cause of you brown spots (click here to read). The second is a link to show you specific lawn disease or fungus problems (click here to read).

Hope these two postings help you answer your lawn brown spot questions.

Brown Patch on Tall Fescue – Circular patches of dead grass are a symptom of several lawn fungus problems such as Brown Patch and Summer Patch show up during periods of warm temperatures and high humidity.

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Ashton,
My lawn was in great shape and then I used scotts weed and feed around may 11. I think the weed and feed is browning the lawn. It seems very consistent through out the lawn. We have been getting a crazy amount of rain here on Long Island and has been steady in the mid 70’s but starting tomorrow we are moving into 80’s and clear. What product should I use to correct this? Or do you recommend waiting a few weeks then applying summer guard. Please help, I would like to get the lawn back on track before we get into the hot summer months.

Hi Joe I am not sure what may be causing your lawn to brown. Turf Builder SummerGuard would provide protection from the kind of insects that can cause your lawn to brown and thin. You can apply 6 weeks after your last feeding. I am wondering if you have a fungus problem. Look for spots on grass blades that are in the process of turning yellow then brown. Scotts Lawn Fungus Control would stop this problem. Good luck.

I am currently suffering from the same issue. My lawn was thick, lush and a beautiful dark green. To be honest is was a pain to mow since it was so thick. Two weeks ago, I noticed there were a few yellowish-dry looking patches, it doesnt seem possible that the lawn was dry with all the rain we’ve been getting on Long Island. Then I started to consider my application of Scotts with the Halt Crabgrass killer and figured maybe it was working to prevent weeds from forming. My neighbors a big lawn guy as well, and he seems to think some type of disease or perhaps the lawn was too thick and began to smother itself. Do you think I should attempt the Fungus Control as well?
Thanks

Ashton- it was not a fungus. It was a grub problem for my lawn. The blades of grass were brown like straw and there was no specific pattern. I also carefully examined the other blades of grass and they were fine. not brown then green, etc I then used a flat shovel and dug up a square of the lawn. Underneath the grass was grubs. Treated for grubs.

hello, I live in south florida and have st Augustine grass. we went away for 10 days and came home to a side yard that is straw brown and looks dead with sprigs of green patches. the area under the tree remained to grow and looks fine and the area that borders the drive way is still green. the grass was put in maybe 3 months ago by a neighbor since we share that side it looked fine before we left???? can I save this area and bring it back to life? please help!
thank you

Hi jencfk
Sorry about your grass. Since your problem is mainly in the sunny areas, it is likely chinch bugs. Hopefully you can treat before they kill your lawn. Put down Ortho Bug B Gon MAX and water after spreading. Then feed your lawn Scotts GreenMAX. Hope this helps.

I have found that the brown spots have been appearing on my lawn because of my two dogs urinating in the same place. The spots are a huge mess and look really dreadful. I spent years trying to sort this out by rushing after the dogs and sprinkling water on the patches, just after the dogs had been for a pee…

…until I found Dog Rocks. They are a really cool product which just simply stop the dog’s pee from messing up the lawn. I cannot recommend them enough. Have a look online – they are available to order.

I’m into another season with the lawn looking good after 3 consecutives years of severe brownout each of the last 3 summers and seeding in the fall. Last applied Turf Builder 5 wks ago and we’ve had nice rain and almost 7″ in June. I put down Grub Control in early June. Going forward, you told me in year’s past that my brownout is probably fungus as it starts in August when it’s real humid. When should I apply the Fungus Control and how often? Also, considering no fert for the 1st time this summer as my brownout in previous year’s happened a few wks after my July fertilizer treatment…any thoughts?

Hi Mike Farish Suggest you get the Lawn Fungus Control down when you see the first sign of a “patch” forming. Sometimes the grass in these patches will first take on a “darker, smoky look” or it will look a bit stressed. This is sometimes easier to see with sunglasses. Or, you could apply when you are starting to see high humidity/temps and night temps/humidity that does not drop much from daytime. Hope this helps.

We found the same problem Chris – dogs had been ruining our lawn for years all whilst we were frantically trying out new grass/fertilizer – the lot! We’ve been using Dog Rocks for a long time with great results. Just need to stop them digging the grass now…!

Ashton,
I have missed fertilizing this Spring season because i was so busy with work. I have recently bought the Turf builder weed and feed. Is it too late to fertilize now? I am in the Northeast. Also it has been raining every day for the last week. On the bag, it says that it should not rain for a day after putting down fertilizer. Is that because the rain washes away the fertilizer? Thanks.

Hi Lee
You can still put down the weed & feed. The reason you do not want rain or irrigation for 24 hours after applying is you want the weed control to have time to be absorbed into the weed leaves (that is why you apply to moist foliage so the particles will stick on the weed leaves, putting down when there is morning dew is great). The only caution I would give is to not apply if your temps are getting anywhere near 90 or above that day, temps in the 70’s to low 80’s are best.

Thanks for the reply Ashton. One more question about the turf builder weed and feed. On the bag, it says you cannot use that feed more than twice a year. Reading your posts, it sounds like we are suppose to feed every 6 weeks. Does the bag mean you just cannot use weed and feed more than twice a year but you can use other feed such as summer guard / winter guard feed?

Hi Lee The twice a year note on the Turf Builder Weed & Feed bag is for the weed control portion, which should not be needed more than twice a year. You are right, it is best to feed your lawn one of the Turf Builder products on a 6 to 8 week schedule during the growing season.

As we discussed, treated the grubs and the treatment treated for all other types of bugs. I am at my 6-8 week cycle and I would like to fertilize. What product would you recommend to keep the remaining grass green and strong for the hot weather here on Long Island this time of year?

Hi Joe F… If you had not treated for bugs, I would suggest Turf Builder SummerGuard, if you have treated for bugs with Ortho Bug B Gon MAX and it has been 6 to 8 weeks since your last feeding, you can feed with Turf Builder or Scotts GreenMAX. I would only wait a week between putting down GrubEx and feeding.

HI Ashton, I live in Missouri and we have had a ton of rain. Right after the rain stopped and the July weather started heating up my grass began forming dead brown spots. What could be the issue and what do I need to due to get my lawn green again?

Hi Jonathan Abbott
Thanks for giving me your location. Lawns in your area can suffer from both lawn fungus problems and lawn insect problems this time of year. With your weather conditions my first suggestion would be to check for lawn fungus. Look for circular shaped patches in the grass that can be up to 12 inches in diameter or look for brown or white spots/blotches on individual grass blades. Scotts Lawn Fungus Control can help keep this condition from spreading. My second suggestion is to consider lawn insects. If you have been seeing tan moths fly from the lawn in the evening when you mow, this could be a sign of sod webworms or cutworms. Ortho Bug B Gon MAX will take care of them. Lawns in your area like to be fed two or three times in late summer/fall. A good schedule would be: Sept 1, Oct 15 and the end of November.

Hi. These brown spots can be caused by dogs urine burning the grass. Dog Rocks are a 100% natural hassle free solution to this. They are just placed in the dogs water bowl. Please see our website for more information.

Hi Jonathan Abbott
If you can determine which of the two situations you have (spots on grass blades and/or circular brown spots OR lawn moths when you mow) you can go with just the one product for that problem. If you decide you need both products, it is best to allow a week between applications. Both products need to be watered after spreading.

Hi Jonathan Abbott
Grass in your area will recover from some disease and insect problems as the growing conditions in fall become more favorable. Unfortunately sometimes lawn sections may not recover and will need to be seeded in fall. It is likely too early to tell your situation. The main thing you will be able to do to help your lawn recover is feed at the beginning of September with Turf Builder and then follow up with two more feedings at 6 week intervals with Turf Builder or Turf Builder WinterGuard.

Hi Jonathan Abbot
Yes you can use Turf Builder SummerGuard for a light summer feeding and to kill any insects. Allow a week between spreading these two products. Be sure to water after spreading to both activate the insect control and the feeding.

Hi Ashton,
I am having clover problems all over my yard. I have patches of clover here and there. I have tried using Ortho weed b gon Max but it did not work on the clovers at all. I was thinking that Turf builder weed and feed might help but it has been raining like crazy here and 90 degree weather so i have not been able to put it down. What is the best way to get rid of clover? Thanks.

Hi Lee… There are many kinds of clover. The product that I have used with lots of success is Ortho Weed B Gon Chickweed Clover and Oxalis Killer. I have used it with the Ortho Dial N Spray hose end sprayer.

How do you store unused fertilizer? Will taping the opened bag help even though its no longer air tight? How long can I store this fertilizer for? Last fall I had some left over fertilizer that i left in my basement. I tried to use it in the Spring and it caused my grass to brown. I am guessing i cannot store it for that long? Thanks.

If there is a possibility of having insects in your lawn or getting a lawn fungus, would it be reasonable to just put down GrubX and Scotts Fungus control each year as a preventative? My lawn looks good, but occasionally I get some brown spots and don’t know if it is because of insects or fungus. Any suggestions?

Hi John Steger
You can have both lawn insects and a lawn fungus at the same time. If you know your lawn is prone to grub problems and you are getting patch type diseases in the summer, GrubEx and Scotts Lawn Fungus Control can provide prevention.

When is the best time of the day to put down turf builder? Also, lawn was mowed Saturday morning. Do you have to wait a certain amount of days after the lawn is mowed to apply turf builder? Last, how long should I keep the kids off of the lawn once the turf builder is applied? Thanks for the help!

Hi Joe F
Turf Builder can be applied anytime to wet or dry foliage. Watering after applying will get the feeding going. There is no waiting time for kids to go on your lawn after spreading Turf Builder. Some of the combo Turf Builder plus products have specific directions about going back on the lawn after spreading.

I’m in SW CT, we have a had a lot of rain in the last month and a half which has caused both a brown spot fungus issue and an increase of insects. I applied Summerguard this past Thursday and have some questions:

When can I apply Fungus Control as its only been a few days since applying Summerguard?
Do I need to apply the Bug B Gon Granules for another three months control or will the Summerguard provide bug control for three months? (Applied bug b gon previously in April)
If so, when should I apply after putting down Fungus Control?

Hi Bob A
You can put down Lawn Fungus Control a week after Turf Builder with SummerGuard. Turf Builder SummerGuard will give you about 6 weeks of insect control. That will take you to around Mid August. You may need another application of Bug B Gon MAX granules if you are seeing lots of lawn moths in your lawn when you mow. If not, you can skip another application and just do a Turf Builder feeding in late August. Bug B Gon MAX granules provide up to 3 months of protection when you use the “heavy” spreader setting rate.

Ashton,
About 3 weeks ago, I was digging up some weeds in my lawn and I found some beetles in my ground. I got grub EX and sprayed it using the spreader on my lawn. I watered it the day after which it says that activates it. Yesterday, i was digging weeds up again and still saw a bunch of beetles where i was digging. I thought the grub EX was suppose to be able to kill beetles? Did i put down the grub EX too late in the season?

Hi Lee Your application of GrubEx protects against the next round of grubs in late summer that will hatch from eggs of adult Japanese Beetles and several other species of beetles. The beetles you saw are likely “Ground Beetles” that are not damaging your lawn. GrubEx will not kill beetles, just the young grubs after they hatch.

Hi Jon
Banner is a good systemic fungicide. If you catch Brown Patch early enough your grass will grow back in that area. It is worth a try. If you have one of the cool season grasses, like fescue, hold off feeding until we get to early fall. Scotts Lawn Fungus Control is also a systemic that is good on Brown Patch (the active ingredient is different from Banner).

Thanks for the reply. I have 2 more questions.
1. I am planning on doing some seeding in the fall. Should i do it in Sep or Oct? Also i have Turf builder weed and feed left over. Should i apply that 4 weeks after i seed or use the winterguard?

2. I have a whole bunch of clovers in my yard. Should i wait for next spring and use Turf builder with halts? Will that stop the clovers from coming up next spring? Or do i need to use Ortho Weed B Gon Chickweed Clover and Oxalis Killer?

Hi Lee
Early September would be a better seeding time in your area. New grass would have to be mowed 4 times before using a weed and feed. You might save your weed and feed till next spring if you do not have time this fall. I would spray the Clover now with Ortho Weed B Gon Chickweed and Clover Killer. Turf Builder with Halts will not prevent clover. Clover is a perennial plant and comes back each year from the roots.

Hi Ashton, thanks for the reply. I am about to apply a round of weed and feed right now. Can I put down the Ortho Weed B Gon Chickweed and Clover Killer at the same time as the weed and feed or do i have to wait for some time?

Hi Lee… You will see better clover control at this time of year with the Ortho Weed B Gon Chickweed and Clover Killer than with the Weed & Feed. You should allow about a month between applications. Check the labels for time to wait to plant grass seed this September, you may not have enough time to use both products this summer.

I live in zip 10710 and my lawn is looking spotty and slightly weedy. My last weed/fertilizer application was about 7 weeks ago. I want to get it back to being the way it was about 3 months ago(green and lush). It has been extremely hot and humid here in NY and somewhat dry. I have been watering about .5″ every 4 days. What application do you suggest I use now to try and keep my lawn lush and weed free for the rest of the hot summer? Any other recommendations?

Hi Brian V… Suggest you feed with Turf Builder SummerGuard. This will feed your lawn while protecting against the kinds of insects that like to thin the lawn and cause it to turn brown in summer. You can spot spray any weeds with Ortho Weed B Gon MAX plus Crabgrass Killer.

Ashton,
We are in central Texas. I have applied Scott’s Summerguard with Turf Builder and now there are brown, wilting patches. I have pulled the grass and they stolons of the St. Augustine are mushy and brown. We have received alot of rain in the past month and it has been very muggy at night. Is this a fungus problem? If so, what do you reccomend?

Hi Peyton
There are two fungus problems that can show up on St. Augustine when you have the kind of weather conditions you described. One is Brown Patch, which will show up as circular brown areas in your lawn about a foot in diameter that first turn a grey color before turning brown. The second is where individual grass blades have dark colored spots on them and the grass plants start to brown in a more random pattern. Both of these conditions can be treated with Scotts Lawn Fungus Control.

Hi Jac
I like to allow a week between these kinds of applications. Wondering what kind of fungus problem is active in your lawn right now? Earlier in the fall you may have had some Brown Patch in your area, however with the cooler temps this tends to go away on its own. Rust and Powdery Mildew can be a problem in fall. If you have Fescue, you can feed this time of year and both of these problems can be diminished.

Hi Celeste Sodano
Horsetail is very difficult to control. From your Christmas Tree description, I believe that is what you have. I have even heard reports that this weed is difficult to control with a non-selective control like Roundup. I would think that in a lawn the repeated mowing would weaken it since it wants to grow taller than your grass. In your other areas, understand that it puts out a lateral root system between plants that runs parallel to the ground surface. Be careful not to cut this root or break it into smaller pieces as you try to remove it. These smaller pieces will create new plants. Good Luck.

Hi, I live in Worcester, Ma…I treated my lawn with step 1 and step 2 my lawn was fine but after step 3, my husband mowed the lawn and my lawn is no longer green I have huge brown spots all over looks like hay😦 … Do you have any suggestions ?

Hi Kim
Thanks for giving me your location. Sorry to read that your lawn has brown spots now. This time of year there are two possible culprits: Fungus Disease or Insects. With higher temps and humidity conditions my first suggestion would be to check for lawn fungus. Look for circular shaped patches in the grass that can be up to 12 inches in diameter or look for brown or white spots/blotches on individual grass blades. Scotts Lawn Fungus Control can help keep this condition from spreading. My second suggestion is to consider lawn insects. If you have been seeing tan moths fly from the lawn in the evening when you mow, this could be a sign of sod webworms or cutworms. Ortho Bug B Gon MAX will take care of them. Since you fed with Step 3 your lawn will not need another feeding until mid Sept when you put down your Step 4. You might also consider feeding in late October with Super Turf Builder WinterGuard.

I live in Northwest Indiana. Just moved across town to the yard in question. It is a sanding kind of yard. Evidence of ant holes throughout the yard. Just in the back yard that backs up to a large patch of over grown field. Also since last year I have notice that the yard is becoming thinner and can see dead brown grass everywhere. I have out down winter guard last fall, crab grass spring fert several weeks ago. I do have an irrigation system. We go thru heavy droughts in this area in the summer months. Is my issue the soil being sandy, the ants, or wrong products?

Hi Gabriel K
Thanks for giving me your location. Sandy soils do tend to have low nutrient levels so it may take several more feedings for you to see full advantage of your efforts. I would continue to feed this year to further build up your existing grass and then make a decision in late summer/early fall whether to put down grass seed and Scotts Turf Builder Starter Lawn Food. You can control the ants and other lawn insects with Ortho Bug B Gon MAX granules. For your next feeding in several weeks suggest you go with Turf Builder or Scotts GreenMAX. You are also in a location where grubs can be a problem. Read more about them with this blog posting: https://tipsfromashton.wordpress.com/2016/04/12/answers-to-your-grub-questions/

I live atop a small limestone mountain in NW Arkansa. Last fall I tilled the lawn by hand clearing the rocks and pebbles from my yard to a depth of 6 – 12 inches. I reseeded with tall fescue. The following spring I applied weed and feed and by May, my lawn resembled nearby golf courses. Chiggers, however were a major problem, so I applied Ortho BugBGon Max with a tank sprayer. Within 1-2 weeks I began to see brown spots throughout the yard primarily in the sunny locations. Rain was plentiful during this time. Shaded areas were generally sprared and remained green. BugBGon applied to trees prone to webworms in the same area were unaffected.

Now, the grass in sunny areas are completely dead. Except for crabgrass and assorted weeds these areas are mostly bare dirt. Large areas will need to be retilled and reseeded. What might have caused the grass to die in these sunny areas?

Hi Don
Sorry to read about your problem with your Fescue. Northern lawns (like Bluegrass, Fescue and Ryegrass) prefer cooler daytime temps that stay in the 80’s and below. However they tend to slow their growth if the nighttime temps and humidity don’t drop much from the 90’s during the day. Cool night temps that drop back into the 60’s at night can do wonders to help Northern lawns continue active growth even during the dog days of summer. During hot, humid summer weather Fescue can be attacked by a fungus problem called Brown Patch, especially in sunny areas. Fescue likes to get most of it’s feeding in Fall (2 or 3 feedings) and only 1 or 2 feedings in spring. Feeding when the temps and humidity is consistently touching the 90’s can encourage this Brown Patch problem to worsen. This response to high temps is one of the reasons that Fescue can tolerate shady areas better than full sun in the more southern portions of the U.S. The Fescue blends like Scotts Heat-Tolerant Blue and Southern Gold would be a better choice than planting a single Fescue variety that may be more susceptible to fungus problems. When you treat for chiggers and other lawn insects, you might consider using the Bug B Gon MAX Granules. Regarding the Fall Webworms in your trees, many times you can encourage the birds to feed on them by destroying the protective web using a long bamboo pole.